1. Field of the Invention
The present invention relates to a member processing apparatus that switches a plurality of members and selects one member, a lens switching apparatus that switches lenses positioned within an optical path, as well as a laser repair apparatus and a laser inspection apparatus equipped with this lens switching apparatus.
2. Description of the Related Art
Conventionally, in manufacturing processes of semiconductor devices and liquid crystal display devices, laser repair apparatuses, which perform repairs on these devices, as well as laser inspection apparatuses, which perform inspections on these devices, have been used. For example, repairs to parts needing repair are carried out by a laser oscillator in a laser repair apparatus emitting a laser light and this laser light irradiating the parts to be repaired of semiconductor devices or liquid crystal display devices.
In this type of repair operation the magnification of the objective lens positioned in the optical path of the laser light must be switched frequently. Thereupon, a lens switching apparatus is provided between the laser oscillator and the part to be repaired in a laser repair apparatus. This lens switching apparatus is designed to select a lens with a desired magnification from among a plurality of objective lenses with magnifications different from each other and then position that lens in the optical path of the laser light. Conventionally, a rotating type switching device called a “revolver” is known as this type of lens switching apparatus (as an example refer to Japanese Patent Laid-Open Publication No. 2001-243654, in particular, to FIG. 2). A rotating type switching device switches the objective lens positioned in the optical path by mounting a plurality of objective lenses to one circular plate and rotating that circular plate.
This conventional technology has the following types of problems however. In a rotating type lens switching device, positional shifting of the lens occurs making it difficult to position the lens with high precision due to the fact that the circular plate whereon is mounted a plurality of lenses decenters. In addition, because a gear wheel is provided in the mechanism that rotates the circular plate and switches the lens, backlash occurs, making it more difficult to position the lens with high precision. The gear wheel also wears down with the passage of time, deteriorating the positioning accuracy.
Because the positional shifting of the objective lens occurs in a circular path, the mechanism to cancel this positional shifting is a very complex device. Consequently, the cost of the lens switching apparatus increases along with a considerable amount of time being required to adjust the lens position.